Searching is a common way to find various types of data. For example, web search engines help users find web pages based on one or more keywords. Desktop search is a popular way to find data stored on a user's local computer. A commonly cited statistic states that 80% of a company's data is contained in unstructured data, which may be easiest to access using searching. The data for a desktop search may include files and directories, documents, email messages, and many other types of data. A search begins with a search query that contains one or more keywords. A search engine receives the search query and looks up the keywords in an index to identify matching content items. The search engine provides information about the matching content items as search results. For example, a web search engine provides hyperlinks to matching web pages and may display a short description of the web page next to the link. A desktop search engine may display links to local data, including properties of the data, such as the author of a document, the path to a file, and so forth.
Search result highlighting calls a user's attention to occurrences of the keywords used in the search query that are present in the search results by modifying the way that the user interface displays occurrences of the keywords. For example, some applications apply highlighting to occurrences of keywords that appears much like a physical yellow (or other color) highlighter appears to words on paper. Other applications boldface or italicize occurrences of keywords. Highlighting keywords helps the user identify relevant search results quickly by calling out the most relevant parts of potentially long descriptions or content item properties.
A problem with search result highlighting is that it can be loud and overwhelming for the user and does not always add the value intended by the application author. Some applications display colors, bold, or other display effects normally when displaying content item properties, so that the colors or boldface of search result highlighting may detract from the look and feel that the application author intended. For example, Windows Vista displays icons (e.g., the yellow Microsoft Outlook email message icon) next to content items in search results that can have similar colors to a highlight effect. As another example, Windows Explorer displays album ratings as one to five yellow stars and various colors throughout the user interface. Previous solutions modify the highlight effect to reduce the perceived noise while unfortunately correspondingly reducing the ability of the highlighting to catch the user's attention. For example, Microsoft SharePoint boldfaces occurrences of search query keywords in search results. This technique does not work for all languages, such as Chinese. As another example, some applications change the text color of occurrences of keywords in search results. This technique does not work for colorblind users. Both of these methods produce a less noticeable highlight as well as introducing other limitations.